<!DOCTYPE html>
<style>
  #subframe {
    width: 400px;
    height: 500px;
    background-color: blue;
  }

  #scroller {
    height: 200px;
    width: 300px;
    overflow: scroll;
  }
</style>
<div id="scroller">
  <iframe id="subframe"></iframe>
</div>
